Remember our previous question: An 80 kg man is running at 7m.s- A bullet with mass 16 g travels at 500 m.s-. The two objects have the same kinetic energy, but different momenta. In this question, both the man and the bullet have a completely inelastic collision with a crash-test dummy, mass of 80 kg, which is initially at rest. Which will move the crash- test dummy a larger distance: the man or the bullet? (We'll pretend this is a one dimensional collision and forget about falling over.)
a) The bullet: because I've done the calculations
b) The bullet: Ive seen it in the movies: the bullet can knock an 80 kg object over easily
c) The man because I've done the calculations
d) The man: a running man can knock an 80 kg object over easily (I've seen it on the rugbył field!) e) About equat they both have the same energy and the distance travelled afterwards will require work equal to frictional force times distance travelled. So, if friction is equal, they travel the same distance.
f) The bullet pushes it further they both have the same energy but the distance travelled afterwards will require work equal to frictional force times distance travelled. The mass of the man plus the mass of the crash-test dummy is twice that of the bullet plus the dummy, so the former has a larger weight, normal force and frictional force, therefore it moves less to use up the same amount of initial energy